Scientific American Supplement, No. 841, February 13, 1892Various
Science
Scientific American Supplement, No. 841, February 13, 1892
Various
Science -- Periodicals
Sapotiretin is an amorphous compound, insoluble in water, very soluble
in alcohol, less soluble in chloroform, insoluble in ether. Below is
the result of its analysis:
Calculated for Found.
C_{17}H_{32}O_{10}. I. II.
C 51.52 51.51 51.20
H 8.08 8.19 8.34
--_Amer. Chem. Jour._
* * * * *
DETECTION OF PEANUT OIL IN OLIVE OIL.
Holde, after a careful trial of the various processes for detecting
the above adulteration, gives the preference to Renard's, which he
describes as follows:
Ten grms. of the suspected oil, after being saponified, and the fatty
acids separated by hydrochloric acid, are dissolved in 90 per cent.
alcohol, and precipitated by sugar of lead. The oleate of lead is
separated by ether, and the residuum, consisting of palmitic and
arachic acids, is decomposed by hydrochloric acid. The fatty acids are
dissolved, with the aid of heat, in 50 c.c. of 90 per cent. alcohol.
The arachic acid which separates after cooling is filtered out and
washed, first with 90 per cent. and afterward with 70 per cent.
alcohol. It is then dissolved in hot alcohol, and the solution
evaporated in a weighed saucer. The weight of the residuum, after
taking into account the acid dissolved in the alcohol, equals the
whole amount of arachic acid contained in the oil; the melting point
of this residuum should be 70 deg. to 71 deg. C. With this process the author
has always been successful; but when the olive oil contains not more
than 5 to 10 per cent. of peanut oil, it is necessary to make the test
with 40 grms. of the former, otherwise the melting point of the
arachic acid cannot be estimated. Furthermore, the acids which are
separated from the lead salt by hydrochloric acid must be
recrystallized repeatedly with 90 per cent. alcohol, until the melting
point ceases to rise, in case the latter is not found to exceed 70 deg. C.
at the first estimation. When peanut oil is present, the melting point
will always be above 70 deg..--_Chem. Zeit._
* * * * *
HYDROXYLAMINE.
Free hydroxylamine, NH_{2}OH, has been isolated by M. Lobry de Bruyn,
and a preliminary account of its mode of preparation and properties is
published by him in the current number of the _Recueil des travaux
chimiques des Pays-Bas_ (1891, 10, 101). The manner in which the free
base was obtained was briefly as follows. About a hundred grammes of
hydroxylamine hydrochloride, NH_{2}OH.HCl, were dissolved in six
hundred cubic centimeters of warm methyl alcohol. To this solution a
quantity of sodium dissolved in methyl alcohol was added, in such
proportion that the hydrochloride of hydroxylamine was present in
slight excess over and above that required to convert it to sodium
chloride. After deposition of the separated sodium chloride the
solution was decanted and filtered.
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